Decoupler for exhaust pipe of automobiles

ABSTRACT

The invention discloses a decoupler for exhaust pipe of automobiles including a bellows ( 10 ) made of metal and formed in cylindrical and a repeatedly corrugated shapes for absorbing bending and expansion to maintain the exhaust gas to be airtight; an inner sleeve ( 20 ) in a cylindrical shape, disposed inward the bellows ( 10 ) for protecting the bellows ( 10 ) and passing through the exhaust gas at high temperature; a guide member ( 40 ) disposed at the one end of the bellows ( 10 ) for forming circular-arc surfaces ( 41, 42 ) at both ends of a cylindrical portion ( 43 ), with respect to the motion center of the bellows ( 10 ), wrapped outward the bellows ( 10 ); a cover member ( 50 ) disposed at the other end of the bellows ( 10 ), for having inclined sections ( 51  and  52 ) symmetrically formed at the opposing ends of the body portion ( 53 ) thereof at a predetermined angle, wrapped outward the bellows ( 10 ); first mesh ring ( 60 ) and second mesh ring ( 61 ) disposed between the guide member ( 40 ) and the cover member ( 50 ), forming a sliding surface in contact with body portion ( 53 ) of the cover member ( 50 ) and the circular-arc surfaces ( 41, 42 ) of the guide member ( 40 ); and first cushion mesh ring ( 70 ) and second cushion mesh ring ( 72 ), each disposed between inclined sections ( 51  and  52 ) of the cover member ( 50 ) and the first and second mesh rings ( 60, 61 ), made of compressive and expansive material, wherein compression and expansion of the first and second cushion mesh rings ( 70, 71 ) function to absorb the compression and tension displacement from the pitching vibration. The guide member ( 40 ) slides along the first and second mesh rings ( 60, 61 ) to absorb the bending displacement, thereby absorbing the displacements due to the pitching vibration and rolling motion. The present invention has an effect to improve the durability of the exhaust system and passengers&#39; comfort and prolong the life of the exhaust system as well as reduction of the wear and friction noise.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] This invention relates to a decoupler for exhaust pipe ofautomobiles, and more particularly, to the decoupler for effectivelyabsorbing the pitching vibration and rolling motion due to the verticalconnection of the exhaust pipes, thereby improving durability of theexhaust system and passengers' comfort.

[0003] 2. Description of the Prior Art

[0004] Generally, engines of the vehicle are connected to the exhaustpipe employing a muffler for exhausting the exhaust gas from thevehicle. For connection, a decoupler is installed to absorb and bufferthe vibration displacement, impact load or heat deformation.

[0005] The decoupler on this location should absorb vibrations anddisplacement occurring depending on the movement of the exhaust systemdue to the engine and road vibrations. It may involve the excessivedisplacement occurring in any directions such as tension compression,bending, deflection and so on.

[0006] In order to maintain airtight of the exhaust gas and improveabsorbing capability of the vibration displacement, the bellows isusually fabricated from metal.

[0007] A number of attempts have been made in the prior art to design aneffective decoupler. One attempt to solve the problems of the prior artis demonstrated by Korean UM application 2000-2443 in which thedecoupler functionally absorbs the displacement in the bendingdirection.

[0008] In the prior art (FIG. 5), an inner sleeve 20′ in a cylindricalshape is fixed inward the bellows 10′ which maintains the exhaust gas tobe airtight and absorbs the expansion and bending displacement, so as toprotect the bellows and guide the exhaust gas of high temperature topass through.

[0009] A guide member 40′ is located at the one end of the bellows 10′for having a circular-arc surfaces 41′ and 42′ with respect to themotion center C′ of the bellows 10′ to surround the bellows 10′.

[0010] At the other end of the bellows 10′, a cover member 50′ islocated outward the guide member 40′ for having an inclined section 51′at a predetermined angle with respect to the motion center C′ in thefrontward and a buffering protector 54′ integrally bent in the rearward.

[0011] First and second mesh rings 60′ and 61′ are located between therespective ends of the cover member 50′ and the circular-arc surfaces41′ and 42′ of the guide member 40′ respectively, wherein inner surfacesbeing in a contact with the circular-arc surfaces 41′ and 42′ and outersurfaces being fixed at the inclined section 51′ and the bufferingprotector 54′.

[0012] In case that a displacement occurs in the bending directionduring travelling of the vehicles, the circular-arc surfaces 41′ and 42′of the guide member 40′ is slid along the contact surface of the firstand second mesh rings 60′ and 61′, thereby absorbing the impactdisplacement.

[0013] However, Korean UM application 2000-002443 is not configured toabsorb tension or compression displacement and pitching vibration, butthe impact due to the bending displacement.

[0014] FIG. 1 (Prior Art) shows that when the conventional decoupler isvertically mounted in the exhaust pipes, it cannot absorb the pitchingvibration, thereby reducing the durability and vibration absorbing ornoise reduction capabilities.

[0015] It has another disadvantage that the scope to be applied of thedecoupler is very limited.

SUMMARY OF THE INVENTION

[0016] Accordingly, it is an object of the present invention to providea decoupler with cushion mesh rings in which the pitching vibration fromthe engine is effectively absorbed even in a vertical connection to theexhaust pipes, to improve the durability of the exhaust system andpassengers' comfort.

[0017] The another object of the present invention is to provide adecoupler for absorbing various vibration displacements from the engine,thereby increasing the scope to be applied.

[0018] The another object of the present invention is to provide adecoupler with high reliability and productivity.

[0019] In accomplishing these and other objects, according to onepreferred embodiment of the present invention, there is provided adecoupler comprising a bellows 10 made of metal and formed incylindrical and a repeatedly corrugated shapes for absorbing the bendingand expansion to maintain the exhaust gas to be airtight;

[0020] an inner sleeve 20 in a cylindrical shape, disposed inward thebellows for protecting the bellows and passing through the exhaust gasof high temperature;

[0021] a guide member 40 disposed at the one end of the bellows 10 forforming a circular-arc surfaces 41 and 42 at both ends of a cylindricalportion 43 with respect to the motion center of the bellows 10, wrappedoutward the bellows 10;

[0022] a cover member 50 disposed at the other end of the bellows 10,for having inclined sections 51 and 52 symmetrically formed at theopposing ends of the body portion 53 thereof at a predetermined angle,wrapped outward the bellows 10;

[0023] first mesh ring 60 and second mesh ring 61 disposed between theguide member 40 and the cover member 50, forming a sliding surface incontact with the body portion 53 of the cover member 50 and thecircular-arc surfaces 41 and 42 of the guide member 40; and

[0024] first cushion mesh ring 70 and second cushion mesh ring 72, eachdisposed between inclined sections 51 and 52 of the cover member 50 andthe first and second mesh rings 60 and 61, made of compressive andexpansive material.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The present invention will become more fully understood from thedetailed description given hereinbelow and the accompanying drawingswhich are given by way of illustration only, and thus, are notlimitative of the present invention, and wherein:

[0026]FIG. 1 is a schematic view of the decoupler according to thepresent invention;

[0027]FIG. 2 is a sectional view of the decoupler according to thepresent invention;

[0028]FIG. 3 is a conceptual view in which the decoupler absorbs thedisplacements in simultaneously occurrence of the tension and bendingdisplacement; and

[0029]FIG. 4 is a conceptual view in which the decoupler absorbs thedisplacements in simultaneously occurrence of the compression andbending displacement.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] Engines 1 are generally supported by a number of installationsemploying a muffler in the direction of the outlet of the exhaust pipe3. The decoupler 2 connects the engines 1 and the exhaust pipe 3. FIG. 1shows that the exhaust pipe 3 has a converter 5 and a muffler 4 at theend thereof.

[0031] As shown in FIG. 2, a bellows 10 of the decoupler of theautomobile exhaust pipe functions to absorb the displacement in thedirection of the expansion and bending, and prevents the exhaust gasthrough the inner sleeve 20 and the guide member 40.

[0032] The bellows 10 of a repeatedly corrugated shape can readilyaccommodate both axial displacement and bending displacement, andrecovers the original shape when the external forces causingdisplacement are removed.

[0033] An inner sleeve 20 of a cylindrical shape is fixed inward thebellows 10 to protect the bellows 10 and allow the exhaust gas to passthrough. At the rear end of the bellows 10, a rear sleeve 30 isinstalled.

[0034] The inner sleeve 20 (not shown) is symmetrically formed in thelateral direction of the bellows 10, to reduce the exhaust resistanceand induce the exhaust flow smoothly.

[0035] Referring to FIG. 2, a guide member 40 located outward thebellows 10 is moved with the bellows 10 in the bending direction. Theguide member 40 has a configuration in such that a cylindrical portion43 is arranged in the middle of the guide member 40, and circular-arcsurfaces 41 and 42 are arranged on the radius R1 with respect to themotion center C of the bellows 10.

[0036] The circular-arc surfaces 41 and 42 having a predetermined radiusR1 with regard to the motion center C of the bellows 10 slide with thefirst and second mesh rings 60 and 61 to be mentioned later to absorbthe bending impact.

[0037] The bending center is set to a motion center C of the bellows 10to induce an angular motion from the bellows 10 to lower the stress, tomaintain the endurance, with the small number of convolutions in thebellows 10.

[0038] Outwardly disposed from the guide member 40, a cover member 50 isdisposed to wrap the bellows 10, for preventing corrosion from gas oralien substance. The guide member 40 has a cylindrical body portion 53in the middle thereof, inclined sections 51 and 52 symmetrically formedat the opposing ends of the body portion 53, with respect to the motioncenter C of the bellows 10 at a predetermined angle.

[0039] Each of first mesh ring 60 and second mesh ring 61 is disposedbetween the cylindrical body portion 53 and the circular-arc surfaces 41and 42 of the guide member 40. The first and second mesh ring 60 and 61have the same contact with the body portion 53 and are inclined at thesame angle with the circular-arc surfaces 41 and 42 of the guide member40.

[0040] First cushion mesh ring 70 and second cushion mesh ring 71 aredisposed between the cover member 50 and the first and second mesh ring61 and 61, made of compressive and expansive material to absorb theaxial vibration.

[0041] In case that the pitching vibration and rolling displacement areapplied in this condition, the circular-arc surfaces 41 and 42 of theguide member 40 slides along the inner side of the first and second meshrings 60 and 61 to absorb the bending displacement.

[0042] The expansion and compression of the first and second cushionmesh rings 70 and 71 function to absorb the tension and compressiondisplacement from the pitching vibration.

[0043] Referring to FIG. 3, in case that the axial tension displacementand bending displacement simultaneously occur, the second cushion meshring 71 elastically becomes longer, while the first cushion mesh ring 70becomes shorter as much to absorb tension displacement from pitchingvibration, in this condition, the circular-arc surfaces 41 and 42 of theguide member 40 slides along the inner side of the first and second meshrings 60 and 61 to absorb the bending displacement at the bending angle.

[0044] Referring to FIG. 4, in case that the axial compressiondisplacement and bending displacement simultaneously occur, the secondcushion mesh ring 71 elastically becomes shorter, while the firstcushion mesh ring 70 becomes longer as much to absorb the compressiondisplacement from pitching vibration, in this condition, thecircular-arc surfaces 41 and 42 of the guide member 40 slides along theinner side of the first and second mesh rings 60 and 61 to absorb thebending displacement at the bending angle .

[0045] Accordingly, the present invention simultaneously absorbs thepitching vibration and rolling motion occurring from the engines of thevertical exhaust system, thereby improving the durability of the exhaustsystem (FIG. 1).

[0046] Since the center point of the bending displacement is the motioncenter C of the bellows 10, the bending displacement allows the stressto uniformly apply to the bellows 10, thereby prolonging the life of thebellows 10.

[0047] The first and second mesh rings 60 and 61 are made of elasticmaterial in order to absorb the impact due to the engine or roadvibration and expansion and bending displacement, preferably, thematerial made of compressed thin wiring net in a ring shape to haveperpetual resilience and easy molding.

[0048] Due to the repetitive friction applied to the first and secondmesh rings 60 and 61, it is preferable to apply appropriate surfacetreatment material such as the carbon or insulation coating on thesurface. By this configuration, the present invention contributes thesmooth sliding movement the reduction of the wear and friction noise, sothat it guarantees product reliability.

[0049] The first and second cushion mesh rings 70 and 71 should have thecharacteristics of resilience and softness, and is preferably made ofresilient material which has such low density as to expand and compresswithin the range of −1 mm˜1 mm.

[0050] In the decoupler for the exhaust pipe of automobiles, the covermember 50 and the first and second cushion mesh rings 70 and 71 absorbthe axial displacement, such as tension, compression and so on by theexpansion and compression thereof.

[0051] In the present invention, the guide member 40 slides along theinner side of the first and second mesh rings 60 and 61 to absorb thebending displacement. The present invention also absorbs displacementsdue to the pitching vibration and rolling motion.

[0052] Accordingly, the present invention has an effect to improve thedurability of the exhaust system and passengers' comfort and prolong thelife of the exhaust system. The present invention contributes thereduction of the wear and friction noise, so that it guarantees theproduct reliability and the prolonged life of the exhaust pipe.

[0053] The present invention is not limited to these embodiments, and itshould be clear to those skilled in the art that other embodiments arepossible within the spirit and scope of the invention claimed.

What is claimed is:
 1. A decoupler for exhaust pipe of automobiles,comprising: a bellows (10) made of metal and formed in cylindrical and arepeatedly corrugated shapes for absorbing the bending and expansion tomaintain the exhaust gas to be airtight; an inner sleeve (20) in acylindrical shape, disposed inward the bellows (10) for protecting thebellows (10) and passing through the exhaust gas of high temperature; aguide member (40) disposed at the one end of the bellows (10) forforming a circular-arc surfaces (41, 42) at both ends of a cylindricalportion (43) with respect to the motion center of the bellows (10),wrapped outward the bellows (10); a cover member (50) disposed at theother end of the bellows (10), for having inclined sections (51, 52)symmetrically formed at the opposing ends of the body portion (53)thereof at a predetermined angle, wrapped outward the bellows (10);first mesh ring (60) and second mesh ring (61) disposed between theguide member (40) and the cover member (50), forming a sliding surfacein contact with body portion (53) of the cover member (50) and thecircular-arc surfaces (41 and 42) of the guide member (40); and firstcushion mesh ring (70) and second cushion mesh ring (71), each disposedbetween inclined sections (51, 52) of the cover member (50) and thefirst and second mesh rings (60 and 61), made of compressive andexpansive material
 2. A decoupler for exhaust pipe of automobiles asclaimed in claim 1, wherein the first and second cushion mesh rings (70,71) has the resilient and soft characteristics with a low density as tocompress and expand within the range of −1 mm˜1 mm.